Nonwoven having improved softness signals, and methods for manufacturing

ABSTRACT

A method of manufacturing a nonwoven including the steps of: forming a nonwoven web substantially comprised of continuous fibers; applying a bonding pattern to said nonwoven web using a smooth roll and a calender roll wherein said bonding pattern comprises a pattern having unbonded areas; and subjecting the side of said nonwoven web contacted by said smooth roll to a hydraulic treatment at a pressure of between 25 and 75 bars and a total energy of about 0.01-0.04 kwhr/kg., wherein said continuous fibers are comprised of between 97% and 98.5% by weight of an olefin resin comprising substantially of polypropylene and between 1.5% and 3% by weight of a whitener.

RELATED APPLICATIONS

This application is a divisional application based on and claimingpriority to U.S. patent application Ser. No. 13/213,524, filed Aug. 19,2011, which in turn is a non-provisional based on U.S. ProvisionalPatent Application Ser. No. 61/375,564, filed Aug. 20, 2010, thecontents of these applications being incorporated herein by reference intheir entirety.

FIELD OF IN THE INVENTION

The present disclosure is related to patterned nonwoven webs and methodsof manufacturing the same.

BACKGROUND OF THE INVENTION

The business of manufacturing and marketing disposable absorbentarticles for personal care or hygiene (such as disposable diapers,training pants, adult incontinence undergarments, feminine hygieneproducts, breast pads, care mats, bibs, wound dressing products, and thelike) is relatively capital intensive and highly competitive. Tomaintain or grow their market share and thereby maintain a successfulbusiness, manufacturers of such articles must continually strive toenhance their products in ways that serve to differentiate them fromthose of their competitors, while at the same time controlling costs soas to enable competitive pricing and the offering to the market of anattractive value-to-price proposition.

One way in which some manufacturers may seek to enhance such products isthrough enhancements to softness. Parents and caregivers naturally seekto provide as much comfort as they can for their babies, and utilizingproducts such as disposable diapers that they perceive as relativelysoft provides reassurance that they are doing what they can to providecomfort in that context. With respect to other types of disposableabsorbent articles that are designed to be applied and/or worn close theskin, an appearance of softness can reassure the wearer or caregiverthat the article will be comfortable.

Thus, manufacturers may devote efforts toward enhancing the softness ofthe various materials used to make such products, such as various webmaterials, including nonwoven web materials formed from polymer fibers,and laminates thereof, forming the products. Such laminates may include,for example, laminates of polymer films and nonwoven web materialsforming the backsheet components of the products.

It is believed that humans' perceptions of softness of a nonwoven webmaterial can be affected by tactile signals, auditory signals and visualsignals.

Tactile softness signals may be affected by a variety of the material'sfeatures and properties that have effect on its tactile feel, includingbut not limited to loft, fiber thickness and density, basis weight,microscopic pliability and flexibility of individual fibers, macroscopicpliability and flexibility of the nonwoven web as formed by the fibers,surface friction characteristics, number of loose fibers or free fiberends, and other features.

Perceptions of softness also may be affected by auditory signals, e.g.,whether and to what extent the material makes audible rustling,crinkling or other noises when touched or manipulated.

It is believed that perceptions of softness of a material also may beaffected by visual signals, i.e., its visual appearance. It is believedthat, if a nonwoven material looks relatively soft to a person, it ismuch more likely that the person will perceive it as having relativetactile softness as well. Visual impressions of softness may be affectedby a variety of features and properties, including but not limited tocolor, opacity, light reflectivity, refractivity or absorption, apparentthickness/caliper, fiber size and density, and macroscopic physicalsurface features.

As a result of the complexity of the mix of the above-describedcharacteristics, to the extent softness is considered an attribute of anonwoven web material, it may elude precise measurement orquantification. Although several methods for measuring and evaluatingmaterial features that are believed to affect softness signals have beendeveloped, there are no standard, universally accepted units or methodsof measurement for softness. It is a subjective, relative concept,difficult to characterize in an objective way. Because softness isdifficult to characterize, it can also be difficult to affect in apredictable way, through changes or adjustments to specifications inmaterials or manufacturing processes.

Complicating efforts to define and enhance softness is the fact thatdiffering individuals will have differing individual physiological andexperiential frames of reference and perceptions concerning whatmaterial features and properties will cause them to perceive softness toa lesser or greater extent in a material, and relative other materials.

Various efforts have been made to provide or alter features of nonwovenweb materials with the objective of enhancing consumer perceptions ofsoftness. These efforts have included selection and/or manipulation offiber chemistry, basis weight, loft, fiber density, configuration andsize, tinting and/or opacifying, embossing or bonding in variouspatterns, etc.

For example, one approach to enhancing perceived softness of a nonwovenweb has involved simply increasing the basis weight of the web,otherwise manufactured through a spunlaid/spunbond process that includesformation of a batt of loose spun fibers and then consolidating bycalender-bonding in a pattern. All other variables remaining constant,increasing the basis weight of such a web will have the effect ofincreasing the number of fibers per unit surface area, andcorrespondingly, increasing apparent thickness, fiber density and/orloft. This approach might be deemed effective if the only objective isincreasing depth and/or loft signals affecting perceptions of softness,i.e., simply increasing the basis weight of a spunbond nonwoven is oneway to increase its depth or loft. However, among the costs involved inproducing nonwoven web material formed of polymer fibers is the cost ofthe polymer resin(s) from which the fibers are spun. Higher basis weightnonwovens require more resin to produce, and therefore, cost more perunit. Thus, attempting to enhance perceived softness by increasingnonwoven basis weight is incompatible with the ever-present objective ofcontrolling or reducing costs.

Another approach has involved forming a nonwoven web of “bicomponent”polymer fibers, by spinning such fibers, laying them to form a batt andthen consolidating them by calender-bonding with a pattern, to providevisual effects. Such bicomponent polymer fibers are formed by spinneretsthat have two side-by-side sections, that express a first polymer on oneside and a second polymer on the other, to form a fiber having a crosssection of the first polymer on one side and the second polymer on theother (hence the term “bicomponent”). The respective polymers may beselected so as to have differing melting temperatures and/orexpansion-contraction rates. These differing attributes of the twopolymers cause the bicomponent fiber products to curl in the spinningprocess, as they exit the spinnerets and cool. The resulting curledfibers then may be laid down in a batt and calender-bonded in a pattern.It is thought that the curl in the fibers adds loft and fluff to theweb, enhancing softness visual and tactile softness signals.

In another approach relating to a backsheet laminate of a film and anon-woven web, prior to lamination with a nonwoven web the film isprinted with a subtle pattern which, following lamination with thenonwoven web, is visible therethrough and simulates actual shading thatwould occur on the nonwoven web surface under various lightingconditions, as if it actually bore a pattern of three-dimensionalsurface features. The desired effect is to enhance visual softnesssignals.

Still another approach has involved adding and blending in a whitetinting/opacifying agent (for example, titanium dioxide) to the polymerused to form a base layer of fibers forming the nonwoven web, formingthe base layer, then forming additional layers by laying down fibersformed of untinted polymer over the base layer, to form a multi-layerbatt. Following formation of the multi-layer batt, it is calender-bondedin a pattern, and then subjected to a hydroenhancing or hydroengorgementprocess to fluff the fibers and increase caliper and loft. It wasthought that the presence of untinted, relatively translucent, shinyfibers laid over and interspersed with the base layer of tinted fibers,together with the hydroenhancing/hydroengorgement process, createsvisual effects tending to enhance the perception of loft and/or depth.It is also believed that the hydroenhancing/hydroengorgement processactually increases loft and/or caliper, enhancing visual and tactilesoftness signals.

Still another approach has related to the manner in which products arepackaged. Typically, absorbent products such as diapers and femininehygiene products are packaged in stacked groups. During packaging, thestacks are usually compressed along a direction approximately orthogonalto the major portions of the surfaces formed by nonwovens, such that thecaliper and loft of the nonwovens tends to be reduced by compressionwhen packaged. The effect of the compression may subsist after removalof the product from a package, adversely affecting softness signals.Thus, it was thought that reducing the amount of compression inpackaging would help to preserve caliper and loft of the nonwovens, andthus preserve the appearance of softness. It will be appreciated,however, that reducing the compression in packaging necessarily has theeffect of either reducing the number of products per package, orincreasing package size—both of which increase the per-product cost.

The approaches described above have had varying degrees of success, buthave left room for improvement in enhancing visual and/or tactilesoftness signals. Additionally, many current methods for enhancingsoftness signals in a nonwoven web have the undesirable effect ofdecreasing desirable mechanical properties such as tensile strength.Generally, it is believed that, for any particular nonwoven webmaterial, processing steps that increase softness signals undesirablydecrease strength.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a disposable diaper shown laid outhorizontally in a relaxed state, wearer-facing surfaces up;

FIG. 1B is a plan view of a disposable diaper shown laid outhorizontally in a stretched out, flattened state (stretched out againstelastic contraction induced by the presence of elastic members),wearer-facing surfaces facing the viewer;

FIG. 2A is a cross section of the diaper depicted in FIGS. 1A and 1B,taken through line 2-2 in those figures;

FIG. 2B is a schematic cross section of a portion of a laminate of apolymeric film and a nonwoven web, taken through a path of bondimpressions;

FIG. 3A is a schematic depiction of a pattern(s) that may be machined,etched, engraved or otherwise formed on the working surface of acalender-bonding roller;

FIG. 3B is a schematic depiction of a pattern(s) of bond impressionsthat may be impressed on a nonwoven web;

FIG. 4A is an image of a nonwoven web sample taken using equipmentdescribed in the Average Measured Height Method set forth herein,illustrating an outline of an unbonded area; and

FIG. 4B is an image of a nonwoven web sample taken using equipmentdescribed in the Average Measured Height Method set forth herein,illustrating outlines of individual bond impressions.

DETAILED DESCRIPTION OF THE INVENTION Definitions

“Absorbent article” refers to devices that absorb and contain bodyexudates, and, more specifically, refers to devices that are placedagainst or in proximity to the body of the wearer to absorb and containthe various exudates discharged from the body. Absorbent articles mayinclude diapers, training pants, adult incontinence undergarments andpads, feminine hygiene products, breast pads, care mats, bibs, wounddressing products, and the like. As used herein, the term “exudates”includes, but is not limited to, urine, blood, vaginal discharges,breast milk, sweat and fecal matter.

“Absorbent core” means a structure typically disposed between a topsheetand backsheet of an absorbent article for absorbing and containingliquid received by the absorbent article. The absorbent core may alsoinclude a cover layer or envelope. The cover layer or envelope maycomprise a nonwoven. In some examples, the absorbent core may includeone or more substrates, an absorbent polymer material, and athermoplastic adhesive material/composition adhering and immobilizingthe absorbent polymer material to a substrate, and optionally a coverlayer or envelope.

“Absorbent polymer material,” “absorbent gelling material,” “AGM,”“superabsorbent,” and “superabsorbent material” are used hereininterchangeably and refer to cross linked polymeric materials that canabsorb at least 5 times their weight of an aqueous 0.9% saline solutionas measured using the Centrifuge Retention Capacity test (Edana441.2-01).

“Absorbent particulate polymer material” is used herein to refer to anabsorbent polymer material which is in particulate form so as to beflowable in the dry state.

“Absorbent particulate polymer material area” as used herein refers tothe area of the core wherein the first substrate and second substrateare separated by a multiplicity of superabsorbent particles. There maybe some extraneous superabsorbent particles outside of this area betweenthe first substrate 64 and second substrate.

“Airfelt” is used herein to refer to comminuted wood pulp, which is aform of cellulosic fiber.

“Average Measured Height” is an average difference in z-direction heightbetween raised, unbonded areas, and bond impressions, of a nonwoven webcomponent of a laminate of a polymeric film and a nonwoven web, measuredand calculated according to the Average Measured Height Method set forthherein.

“Bicomponent” refers to fiber having a cross-section comprising twodiscrete polymer components, two discrete blends of polymer components,or one discrete polymer component and one discrete blend of polymercomponents. “Bicomponent fiber” is encompassed within the term“Multicomponent fiber.” A Bicomponent fiber may have an overall crosssection divided into two or more subsections of the differing componentsof any shape or arrangement, including, for example, coaxialsubsections, core-and-sheath subsections, side-by-side subsections,radial subsections, etc.

“Bond Area Percentage” on a nonwoven web is a ratio of area occupied bybond impressions, to the total surface area of the web, expressed as apercentage, and measured according to the Bond Area Percentage methodset forth herein.

“Bond Length Ratio” is a value expressed as rage, and is the ratio ofthe sum of lengths of a repeating series of bond impressions on anonwoven web along a theoretical line segment through and connecting thebond impressions in the series, and extending from a leading edge of thebond impression beginning the series, to a leading edge of the bondimpression beginning the next adjacent repeating series, to the totallength of the line segment, and is determined according to the BondPath/Bond Length Ratio measurement method set forth herein. By way ofnon-limiting illustration FIG. 3B in which length D₀ is the length of aline segment and lengths D₁, D₂ and D₃ are lengths along the linesegment of three bond impressions in a hypothetical repeating series ofsubstantially identical bond impressions 100 a as shown in FIG. 3B, aBond Length Ratio may be calculated as [(D₁+D₂+D₃)/D₀]×100%. It will benoted that if all bond impressions 100 a as exemplified in FIG. 3B areidentical in area, shape and spacing, any group of them in any numberalong a line segment will constitute a repeating series. However, bondimpressions forming a path also may have differing areas, shapes and/orspacing, and it may be necessary to identify a repeating series of bondimpressions of any other particular number in order to determine BondLength Ratio.

“Bonding roller,” “calender roller” and “roller” are usedinterchangeably.

“Cross direction”—with respect to a web material, refers to thedirection along the web material substantially perpendicular to thedirection of forward travel of the web material through themanufacturing line in which the web material is manufactured.

“Disposable” is used in its ordinary sense to mean an article that isdisposed or discarded after a limited number of usage events overvarying lengths of time, for example, less than about 20 events, lessthan about 10 events, less than about 5 events, or less than about 2events.

“Diaper” refers to an absorbent article generally worn by infants andincontinent persons about the lower torso so as to encircle the waistand legs of the wearer and that is specifically adapted to receive andcontain urinary and fecal waste. As used herein, term “diaper” alsoincludes “pant” which is defined below.

“Fiber” and “filament” are used interchangeably.

“Film”—means a skin-like or membrane-like layer of material formed ofone or more polymers, which does not have a form consistingpredominately of a web-like structure of consolidated polymer fibersand/or other fibers.

“Length” or a form thereof, with respect to a diaper or training pant,refers to a dimension measured along a direction perpendicular to thewaist edges and/or parallel to the longitudinal axis.

“Machine direction”—with respect to a web material, refers to thedirection along the web material substantially parallel to the directionof forward travel of the web material through the manufacturing line inwhich the web material is manufactured.

“Monocomponent” refers to fiber formed of a single polymer component orsingle blend of polymer components, as distinguished from Bicomponent orMulticomponent fiber.

“Multicomponent” refers to fiber having a cross-section comprising morethan one discrete polymer component, more than one discrete blend ofpolymer components, or at least one discrete polymer component and atleast one discrete blend of polymer components. “Multicomponent fiber”includes, but is not limited to, “Bicomponent fiber.” A Multicomponentfiber may have an overall cross section divided into subsections of thediffering components of any shape or arrangement, including, forexample, coaxial subsections, core-and-sheath subsections, side-by-sidesubsections, radial subsections, etc.

A “nonwoven” is a manufactured sheet or web of directionally or randomlyoriented fibers, consolidated and bonded together by friction, cohesion,adhesion or one or more patterns of bonds and bond impressions createdthrough localized compression and/or application of heat or heatingenergy, or a combination thereof. The term does not include fabricswhich are woven, knitted, or stitch-bonded with yarns or filaments. Thefibers may be of natural or man-made origin and may be staple orcontinuous filaments or be formed in situ. Commercially available fibershave diameters ranging from less than about 0.001 mm to more than about0.2 mm and they come in several different forms: short fibers (known asstaple, or chopped), continuous single fibers (filaments ormonofilaments), untwisted bundles of continuous filaments (tow), andtwisted bundles of continuous filaments (yarn). Nonwoven fabrics can beformed by many processes such as meltblowing, spunbonding, solventspinning, electrospinning, and carding. The basis weight of nonwovenfabrics is usually expressed in grams per square meter (gsm).

“Opacity” is a numeric value relating to the ability of a web materialto transmit light therethrough, measured according the OpacityMeasurement Method set forth herein.

“Pant” or “training pant”, as used herein, refer to disposable garmentshaving a waist opening and leg openings designed for infant or adultwearers. A pant may be placed in position on the wearer by inserting thewearer's legs into the leg openings and sliding the pant into positionabout a wearer's lower torso. A pant may be preformed by any suitabletechnique including, but not limited to, joining together portions ofthe article using refastenable and/or non-refastenable bonds (e.g.,seam, weld, adhesive, cohesive bond, fastener, etc.). A pant may bepreformed anywhere along the circumference of the article (e.g., sidefastened, front waist fastened). While the terms “pant” or “pants” areused herein, pants are also commonly referred to as “closed diapers,”“prefastened diapers,” “pull-on diapers,” “training pants,” and“diaper-pants”. Suitable pants are disclosed in U.S. Pat. No. 5,246,433,issued to Hasse, et al. on Sep. 21, 1993; U.S. Pat. No. 5,569,234,issued to Buell et al. on Oct. 29, 1996; U.S. Pat. No. 6,120,487, issuedto Ashton on Sep. 19, 2000; U.S. Pat. No. 6,120,489, issued to Johnsonet al. on Sep. 19, 2000; U.S. Pat. No. 4,940,464, issued to Van Gompelet al. on Jul. 10, 1990; U.S. Pat. No. 5,092,861, issued to Nomura etal. on Mar. 3, 1992; U.S. Patent Publication No. 2003/0233082 A1,entitled “Highly Flexible And Low Deformation Fastening Device”, filedon Jun. 13, 2002; U.S. Pat. No. 5,897,545, issued to Kline et al. onApr. 27, 1999; U.S. Pat. No. 5,957,908, issued to Kline et al on Sep.28, 1999.

“Substantially cellulose free” is used herein to describe an article,such as an absorbent core, that contains less than 10% by weightcellulosic fibers, less than 5% cellulosic fibers, less than 1%cellulosic fibers, no cellulosic fibers, or no more than an immaterialamount of cellulosic fibers. An immaterial amount of cellulosic materialwould not materially affect the thinness, flexibility, or absorbency ofan absorbent core.

“Substantially continuously distributed” as used herein indicates thatwithin the absorbent particulate polymer material area, the firstsubstrate 64 and second substrate 72 are separated by a multiplicity ofsuperabsorbent particles. It is recognized that there may be minorincidental contact areas between the first substrate 64 and secondsubstrate 72 within the absorbent particulate polymer material area.Incidental contact areas between the first substrate 64 and secondsubstrate 72 may be intentional or unintentional (e.g. manufacturingartifacts) but do not form geometries such as pillows, pockets, tubes,quilted patterns and the like.

“Tensile Strength” refers to the maximum tensile force (Peak Force) amaterial will sustain before tensile failure, as measured by the TensileStrength Measurement Method set forth herein.

“Thickness” and “caliper” are used herein interchangeably.

“Total Stiffness” refers to the measured and calculated value relatingto a material, according to the Stiffness measurement method set forthherein.

“Width” or a form thereof, with respect to a diaper or training pant,refers to a dimension measured along a direction parallel to the waistedges and/or perpendicular to the longitudinal axis.

“Z-direction,” with respect to a web, means generally orthogonal orperpendicular to the plane approximated by the web in the machine andcross direction dimensions.

Examples of the present invention include disposable absorbent articleshaving improved softness attributes.

FIG. 1A is a perspective view of a diaper 10 in a relaxed, laid-openposition as it might appear opened and lying on a horizontal surface.FIG. 1B is a plan view of a diaper 10 shown in a flat-out, uncontractedstate (i.e., without elastic induced contraction), shown with portionsof the diaper 10 cut away to show underlying structure. The diaper 10 isdepicted in FIG. 1B with its longitudinal axis 36 and its lateral axis38. Portions of the diaper 10 that contact a wearer are shown orientedupwards in FIG. 1A, and are shown facing the viewer in FIG. 1B. FIG. 2Ais a cross section of the diaper taken at line 2-2 in FIG. 1B.

The diaper 10 generally may comprise a chassis 12 and an absorbent core14 disposed in the chassis. The chassis 12 may comprise the main body ofthe diaper 10.

The chassis 12 may include a topsheet 18, which may be liquid pervious,and a backsheet 20, which may be liquid impervious. The absorbent core14 may be encased between the topsheet 18 and the backsheet 20. Thechassis 12 may also include side panels 22, elasticized leg cuffs 24,and an elastic waist feature 26. The chassis 12 may also comprise afastening system, which may include at least one fastening member 46 andat least one landing zone 48.

The leg cuffs 24 and the elastic waist feature 26 may each typicallycomprise elastic members 28. One end portion of the diaper 10 may beconfigured as a first waist region 30 of the diaper 10. An opposite endportion of the diaper 10 may be configured as a second waist region 32of the diaper 10. An intermediate portion of the diaper 10 may beconfigured as a crotch region 34, which extends longitudinally betweenthe first and second waist regions 30 and 32. The crotch region 34 mayinclude from 33.3% to 50% of the overall length of the diaper 10, andeach of waist regions 30, 32 may correspondingly include from 25% to33.3% of the overall length of the diaper 10.

The waist regions 30 and 32 may include elastic elements such that theygather about the waist of the wearer to provide improved fit andcontainment (elastic waist feature 26). The crotch region 34 is thatportion of the diaper 10 which, when the diaper 10 is worn, is generallypositioned between the wearer's legs.

The diaper 10 may also include such other features including front andrear ear panels, waist cap features, elastics and the like to providebetter fit, containment and aesthetic characteristics. Such additionalfeatures are described in, e.g., U.S. Pat. Nos. 3,860,003 and 5,151,092.

In order to apply and keep diaper 10 in place about a wearer, the secondwaist region 32 may be attached by the fastening member 46 to the firstwaist region 30 to form leg opening(s) and an article waist. Whenfastened, the fastening system carries a tensile load around the articlewaist.

According to some examples, the diaper 10 may be provided with are-closable fastening system or may alternatively be provided in theform of a pant-type diaper. When the absorbent article is a diaper, itmay comprise a re-closable fastening system joined to the chassis forsecuring the diaper to a wearer. When the absorbent article is apant-type diaper, the article may comprise at least two side panelsjoined to the chassis and to each other to form a pant. The fasteningsystem and any component thereof may include any material suitable forsuch a use, including but not limited to plastics, films, foams,nonwoven, woven, paper, laminates, stretch laminates, activated stretchlaminates, fiber reinforced plastics and the like, or combinationsthereof. In some examples, the materials making up the fastening devicemay be flexible. In some examples, the fastening device may comprisecotton or cotton-like materials for additional softness or consumerperception of softness. The flexibility may allow the fastening systemto conform to the shape of the body and thus, reduce the likelihood thatthe fastening system will irritate or injure the wearer's skin.

For unitary absorbent articles, the chassis 12 and absorbent core 14 mayform the main structure of the diaper 10 with other features added toform the composite diaper structure. While the topsheet 18, thebacksheet 20, and the absorbent core 14 may be assembled in a variety ofwell-known configurations, preferred diaper configurations are describedgenerally in U.S. Pat. No. 5,554,145 entitled “Absorbent Article WithMultiple Zone Structural Elastic-Like Film Web Extensible Waist Feature”issued to Roe et al. on Sep. 10, 1996; U.S. Pat. No. 5,569,234 entitled“Disposable PuIl-On Pant” issued to Buell et al. on Oct. 29, 1996; andU.S. Pat. No. 6,004,306 entitled “Absorbent Article WithMulti-Directional Extensible Side Panels” issued to Robles et al. onDec. 21, 1999.

The topsheet 18 may be fully or partially elasticized and/or may beforeshortened to create a void space between the topsheet 18 and theabsorbent core 14. Exemplary structures including elasticized orforeshortened topsheets are described in more detail in U.S. Pat. No.5,037,416 entitled “Disposable Absorbent Article Having ElasticallyExtensible Topsheet” issued to Allen et al. on Aug. 6, 1991; and U.S.Pat. No. 5,269,775 entitled “Trisection Topsheets for DisposableAbsorbent Articles and Disposable Absorbent Articles Having SuchTrisection Topsheets” issued to Freeland et al. on Dec. 14, 1993.

The backsheet 20 may be joined with the topsheet 18. The backsheet 20may serve prevent the exudates absorbed by the absorbent core 14 andcontained within the diaper 10 from soiling other external articles thatmay contact the diaper 10, such as bed sheets and clothing. Referring toFIG. 2B, the backsheet 20 may be substantially impervious to liquids(e.g., urine) and comprise a laminate of a nonwoven 21 and a thinpolymeric film 23 such as a thermoplastic film having a thickness ofabout 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Suitablebacksheet films include those manufactured by Tredegar Industries Inc.of Terre Haute, Ind. and sold under the trade names X15306, X10962, andX10964. Other suitable backsheet materials may include breathablematerials that permit vapors to escape from the diaper 10 while stillpreventing liquid exudates from passing through the backsheet 20.Exemplary breathable materials may include materials such as woven webs,nonwoven webs, composite materials such as film-coated nonwoven webs,and microporous films such as manufactured by Mitsui Toatsu Co., ofJapan under the designation ESPOIR and by EXXON Chemical Co., of BayCity, Tex., under the designation EXXAIRE. Suitable breathable compositematerials comprising polymer blends are available from ClopayCorporation, Cincinnati, Ohio under the name HYTREL blend P1 8-3097.Other examples of such breathable composite materials are described ingreater detail in PCT Application No. WO 95/16746, published on Jun. 22,1995 in the name of E.I. DuPont. Other breathable backsheets includingnonwoven webs and apertured formed films are described in U.S. Pat. No.5,571,096 issued to Dobrin et al. on Nov. 5, 1996.

In some examples, the backsheet of the present invention may have awater vapor transmission rate (WVTR) of greater than about 2,000 g/24h/m2, greater than about 3,000 g/24 h/m2, greater than about 5,000 g/24h/m2, greater than about 6,000 g/24 h/m2, greater than about 7,000 g/24h/m2, greater than about 8,000 g/24 h/m2, greater than about 9,000 g/24h/m2, greater than about 10,000 g/24 h/m2, greater than about 11,000g/24 h/m2, greater than about 12,000 g/24 h/m2, greater than about15,000 g/24 h/m2, measured according to WSP 70.5 (08) at 37.8° C. and60% Relative Humidity.

Suitable non-woven materials useful in the present invention include,but are not limited to SMS material, comprising a spunbonded, amelt-blown and a further spunbonded layer. In some examples, permanentlyhydrophilic non-wovens, and in particular, nonwovens with durablyhydrophilic coatings may be desirable. Another suitable embodimentcomprises a SMMS-structure. In some examples, the non-wovens may beporous.

In some examples, suitable non-woven materials may include, but are notlimited to synthetic fibers, such as PE, PET, and PP. As polymers usedfor nonwoven production may be inherently hydrophobic, they may becoated with hydrophilic coatings. One way to produce nonwovens withdurably hydrophilic coatings, is via applying a hydrophilic monomer anda radical polymerization initiator onto the nonwoven, and conducting apolymerization activated via UV light resulting in monomer chemicallybound to the surface of the nonwoven as described in co-pending U.S.Patent Publication No. 2005/0159720. Another way to produce nonwovenswith durably hydrophilic coatings is to coat the nonwoven withhydrophilic nanoparticles as described in co-pending applications U.S.Pat. No. 7,112,621 to Rohrbaugh et al. and in PCT ApplicationPublication WO 02/064877.

Typically, nanoparticles have a largest dimension of below 750 nm.Nanoparticles with sizes ranging from 2 to 750 nm may be economicallyproduced. An advantage of nanoparticles is that many of them can beeasily dispersed in water solution to enable coating application ontothe nonwoven, they typically form transparent coatings, and the coatingsapplied from water solutions are typically sufficiently durable toexposure to water. Nanoparticles can be organic or inorganic, syntheticor natural. Inorganic nanoparticles generally exist as oxides,silicates, and/or carbonates. Typical examples of suitable nanoparticlesare layered clay minerals (e.g., LAPONITE™ from Southern Clay Products,Inc. (USA), and Boehmite alumina (e.g., Disperal P2™ from North AmericanSasol. Inc.). According to one example, a suitable nanoparticle coatednon-woven is that disclosed in the co-pending patent application Ser.No. 10/758,066 entitled “Disposable absorbent article comprising adurable hydrophilic core wrap” by Ponomarenko and Schmidt.

Further useful non-wovens are described in U.S. Pat. No. 6,645,569 toCramer et al., U.S. Pat. No. 6,863,933 to Cramer et al., U.S. Pat. No.7,112,621 to Rohrbaugh et al., and co-pending patent application Ser.No. 10/338,603 to Cramer et al. and Ser. No. 10/338,610 to Cramer et al.

In some cases, the nonwoven surface can be pre-treated with high energytreatment (corona, plasma) prior to application of nanoparticlecoatings. High energy pre-treatment typically temporarily increases thesurface energy of a low surface energy surface (such as PP) and thusenables better wetting of a nonwoven by the nanoparticle dispersion inwater.

Notably, permanently hydrophilic non-wovens are also useful in otherparts of an absorbent article. For example, topsheets and absorbent corelayers comprising permanently hydrophilic non-wovens as described abovehave been found to work well.

According to one example, the nonwoven may comprise a material thatprovides good recovery when external pressure is applied and removed.Further, according to one example, the nonwoven may comprise a blend ofdifferent fibers selected, for example from the types of polymericfibers described above. In some embodiments, at least a portion of thefibers may exhibit a spiral curl which has a helical shape. In someexamples, the nonwoven may comprise fibers having different degrees ortypes of curling, or both. For example, one embodiment may include amixture of fibers having about 3 to about 5 curls per centimeter (cpc)or about 3.5 to about 4 cpc, and other fibers having about 1.5 to about3.2 cpc or about 2 to about 2.8 cpc.

Different types of curls include, but are not limited to a 2D curl or“flat curl” and a 3D or spiral-curl. According to one example, thefibers may include bicomponent fibers, which are individual fibers eachcomprising different materials, usually a first and a second polymericmaterial. It is believed that the use of side-by-side bi-componentfibers is beneficial for imparting a spiral curl to the fibers.

In order to enhance softness perceptions of the absorbent article,nonwovens forming the backsheet may be hydroenhanced or hydroengorged.Hydroenhanced/hydroengorged nonwovens are described in U.S. Pat. Nos.6,632,385 and 6,803,103, and U.S. Pat. App. Pub. No. 2006/0057921.

A nonwoven may also be treated by a “selfing” mechanism. By “selfing”nonwovens, high densities of loops (>150 in 2) may be formed whichprotrude from the surface of the nonwoven substrate. Since these loopsact as small flexible brushes, they create an additional layer ofspringy loft, which may enhance softness. Nonwovens treated by a selfingmechanism are described in U.S. Pat. App. Pub. No. US 2004/0131820.

Nonwovens also may include a surface coating. In one example, thesurface coating may include a fiber surface modifying agent, thatreduces surface friction and enhances tactile lubricity. Preferred fibersurface modifying agents are described in U.S. Pat. Nos. 6,632,385 and6,803,103; and U.S. Pat. App. Pub. No. 2006/0057921.

A surface coating also may include a surfactant coating. One suchsurfactant coating is available from Schill & Silacher GmbH, Böblingen,Germany, under the Tradename Silastol PST.

Any of the nonwovens described herein may be used for the topsheet,backsheet, or any other portion of the absorbent article comprising anonwoven. In order to achieve improved softness of the absorbentarticle, the nonwovens of the present invention may have a basis weightof greater than about 20 gsm, greater than about 22 gsm, greater thanabout 24 gsm, greater than about 26 gsm, greater than about 28 gsm,greater than about 30 gsm, greater than about 32 gsm.

The absorbent core generally may be disposed between the topsheet 18 andthe backsheet 20. It may include one or more layers, such as a firstabsorbent layer 60 and a second absorbent layer 62.

The absorbent layers 60, 62 may include respective substrates 64, 72, anabsorbent particulate polymer material 66, 74 disposed on substrates 64,72, and a thermoplastic adhesive material 68, 76 disposed on and/orwithin the absorbent particulate polymer material 66, 74 and at leastportions of the substrates 64, 72 as an adhesive for immobilizing theabsorbent particulate polymer material 66, 74 on the substrates 64, 65.

The substrate 64 of the first absorbent layer 60 may be referred to as adusting layer and has a first surface which faces the backsheet 20 and asecond surface which faces the absorbent particulate polymer material66. Likewise, the substrate 72 of the second absorbent layer 62 may bereferred to as a core cover and has a first surface facing the topsheet18 and a second surface facing the absorbent particulate polymermaterial 74.

The first and second substrates 64 and 72 may be adhered to one anotherwith adhesive about the periphery to form an envelope about theabsorbent particulate polymer materials 66 and 74 to hold the absorbentparticulate polymer material 66 and 74 within the absorbent core 14.

The substrates 64, 72 may be of one or more nonwoven materials, and maybe liquid permeable.

As illustrated in FIG. 2A, the absorbent particulate polymer material66, 74 may be deposited on the respective substrates 64, 72 in clusters90 of particles to form a grid pattern comprising land areas 94 andjunction areas 96 between the land areas 94. Land areas 94 are areaswhere the thermoplastic adhesive material does not contact the nonwovensubstrate or the auxiliary adhesive directly; junction areas 96 areareas where the thermoplastic adhesive material does contact thenonwoven substrate or the auxiliary adhesive directly. The junctionareas 96 in the grid pattern contain little or no absorbent particulatepolymer material 66 and 74. The land areas 94 and junction areas 96 canhave a variety of shapes including, but not limited to, circular, oval,square, rectangular, triangular, and the like. First and second layers60, 62 may be combined to form the absorbent core 14. Preferredabsorbent articles and cores are described in U.S. application Ser. No.12/141,122; U.S. Pat. Apps. Pub. Nos. 2004/0167486A1 and 2004/0162536;and PCT Pub. No. WO 2009/060384.

Signal ingredients may be incorporated into one or more components ofthe absorbent article. Signal ingredients may include, but are notlimited to, vitamins A, E, D, and C, panthenol, niacin, omega 3 oils,cocoa butter, beeswax, cashmere, sweet almond oil, jojoba, oatmeal,aloe, cotton, honey, and silk. These signal ingredients may be added toan absorbent article for the purpose of signaling a benefit to theconsumer. As an example, one or more of these signal ingredients may beadded to a lotion that may be applied to an absorbent article component.The signal ingredient alone, or in a lotion, may be applied to thetopsheet, backsheet, or any other component of the absorbent article.The lotion may comprise less than about 0.1% by weight, less than about0.01% by weight, less than about 0.006% by weight, less than about0.005% by weight, less than about 0.004% by weight, less than about0.003% by weight, less than about 0.002% by weight, and less than about0.001% by weight of the signal ingredient.

Additionally, a signal ingredient may, in combination with otherabsorbent article features, result in an unexpected synergy forcommunicating a benefit to the consumer. As an example, consumers mayrespond unexpectedly more favorably to an absorbent article that is thinand perceptibly soft in combination with a communication that lotion inthe diaper comprises vitamin E than they would respond to eithercommunication on its own.

An example of a diaper lotion comprising vitamin E as a signalingredient may include the following formula: PET/StOH Mix (ratio=1.41)94.0% to 99.8% (by weight) Aloe Extract 0.1% to 3.0% (by weight) VitaminE 0.00 1% to 0.1% (by weight). Further, vitamin E may be used in itsnatural form or esters of natural vitamin E may be used (e.g., vitamin Eacetate). U.S. App. Pub. Nos. 2002/0143304; 2004/0175343; 2003/0077307;U.S. Pat. Nos. 5,643,588; 5,635,191; 5,607,760; 6,861,571; and PCTApplication Nos. WO 00/69481; and WO 98/24391 disclose various absorbentarticle lotions that signal ingredients may be added to.

Another way to achieve improved softness of the absorbent article may bethrough a lower in-bag compression. Lower compression rates result in asofter feeling absorbent article. Preferred in-bag compressionpercentages of the present invention are less than about 54%, less thanabout 52%, less than about 50%, less than about 49%, less than about48%, less than about 47%, less than about 46%. For purposes herein,in-bag compression percentage is determined according to the In-BagCompression Measurement Test set forth below.

Enhanced Nonwoven Webs Used for Topsheets and/or Backsheet Laminates

The foregoing description describes features of an absorbent article,any combination of which can be employed to enhance consumer perceptionsof softness of the article. In addition, however, it is believed thatmanufacturing a nonwoven web, which may be used as a component of anabsorbent article including, e.g., a topsheet 18 and/or backsheet 20(see FIGS. 2A, 2B), according to the following description, provides forenhancement of softness signals of the component, and has synergisticeffects with respect to enhancing perceptions of softness of the articleas a whole. At the same time, counterintuitively, features describedbelow enhance tensile strength of the nonwoven web, and consequently, ofthe topsheet, backsheet or other component formed of it. When attemptingto improve softness signals, preserving or enhancing tensile strength ofa nonwoven may be of particular interest in absorbent articles for atleast two reasons. First, the nonwoven web may typically be required tosustain certain minimum tensile forces and undergo sufficiently lowchanges in dimension so as to be effectively processable in downstreammanufacturing operations. Second, the nonwoven web typically may be asubstantial contributor to structural integrity of a backsheet laminatein absorbent products such as disposable diapers, in which the backsheetmay be required to sustain forces resulting from application/donning ona wearer (e.g., when a caregiver tugs on fastening members to apply adiaper), wearer movements, and bulk and weight and bulk contained andsustained by the backsheet when the diaper is loaded with the wearer'sexudates.

As previously noted, a backsheet 20 may be formed of a laminate of anonwoven and a thin polymeric film. In some examples, the polymeric filmmay have a thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0mils). In order to achieve the desired overall visual appearance, theopacity and whiteness of the backsheet laminate may be enhanced byaddition of, for example, calcium carbonate (CaCO₃) to the film duringits formation. Inclusion of fine particles of CaCO₃ cause the formationof micropores about the particles upon stretching, or biaxial stretchingin processing of the film, which serve to make the resulting film air-and vapor-permeable (thus, “breathable”, reducing the likelihood of skinoverhydration and thereby reducing the likelihood of conditions such asdiaper rash). The CaCO₃ particles and the resulting micropores in thefilm also serve to enhance its opacity. Examples of suitable filmsinclude MICROPRO microporous films, and films designated BR137P andBR137U, available from Clopay Corporation, Mason, Ohio.

In some examples, the polymeric film may be formed of components, and asdescribed, in U.S. application Pub. No. 2008/0306463, and may includesome or all of the features and/or components described therein, thatreduce the film's vulnerability to glue “burn-through.”

The nonwoven web may be a hydroengorged spunbond nonwoven with a quiltedbonding pattern and possessing two-sided properties due to a combinationof materials and hydraulic treatment. The nonwoven may be formed to havean outer-facing side/surface having a pronounced quilted appearance andenhanced softness attributes, whereas the inner-facing side/surface manynot necessarily require enhanced softness attributes.

The nonwoven web may be formed from one or more resins of polyolefinsincluding but not limited to polypropylene (PP), polyethylene (PE), andpolyethylene terephthalate (PET), and blends thereof. Resins includingpolypropylene may be particularly useful because of polypropylene'srelatively low cost and surface friction properties of fibers formedfrom it (i.e., they have a relatively smooth, slippery tactile feel).Resins including polyethylene may also be desirable because ofpolyethylene's relative softness/pliability and even moresmooth/slippery surface friction properties. Relative each other, PPcurrently has a lower cost and fibers formed from it have a greatertensile strength, while PE currently has a greater cost and fibersformed from it have a lower tensile strength but greater pliability anda more smooth/slippery feel. Accordingly, it may be desirable to formnonwoven web fibers from a blend of PP and PE resins, finding a balanceof the best proportions of the polymers to balance their advantages anddisadvantages. In some examples, the fibers may be formed of PP/PEblends such as described in U.S. Pat. No. 5,266,392. A suitable spunbondnonwoven may be formed in multiple layers containing differingmaterials. For example, the spunbond nonwoven may have a standardpolypropylene forming the layers on the inner-facing side of thenonwoven, and a polypropylene blend containing softeners for the layersof the outer-facing side of the nonwoven. An exemplary polypropyleneblend containing softeners is ExxonMobil SFT-315; however other resinsand resin blends designed for use in manufacturing soft nonwovens mayalso be used.

A nonwoven may be formed from any of these resins by conventionalspunbonding processes, in which the resin(s) are heated and forced underpressure through spinnerets. The spinnerets eject fibers of thepolymer(s), which are then directed onto a moving belt; as they strikethe moving belt they are laid down in somewhat random orientations toform a spunlaid batt. The batt then may be calender-bonded to form thenonwoven web.

Nonwovens formed of any basis weight may be used. However, as noted inthe background, relatively higher basis weight, while having relativelygreater apparent caliper and loft, also has relatively greater cost. Onthe other hand, relatively lower basis weight, while having relativelylower cost, adds to the difficulty of providing a backsheet that has andsustains a dramatic visual quilted appearance following compression in apackage. It is believed that the combination of features describedherein strikes a good balance between controlling material costs andproviding a dramatic visual quilted appearance when the basis weight ofthe nonwoven used is 30 gsm or less, preferably from 20 to 30 gsm, oreven more preferably from 23 to 27 gsm.

It is believed that the desired overall visual softness signals of abacksheet laminate may be better achieved when the backsheet laminate issubstantially white in color, and has an Opacity of at least 65, morepreferably at least 70, even more preferably at least 73, and still morepreferably at least 75, as measured by the Opacity Measurement Methodset forth below. Accordingly, it may be desirable to add awhite-tinting/opacifying agent also to the polymer(s) forming thepolymeric film, and to all of the polymer(s) supplying all of thespinnerets.

With respect to a nonwoven web that may form a component of an absorbentarticle including a topsheet or a backsheet, it was previously believedthat adding a white tinting agent to only the polymer(s) forming afirst, underlying layer of spunlaid fibers, while adding none to thepolymer(s) forming one or more of the overlying spunlaid layers, helpedenhance visual softness attributes as a result of the relativelytranslucent, shiny untinted fibers interacting with ambient light andthe white-tinted underlying fibers. However, it has been surprisinglydiscovered that the desired visual quilted appearance, manifest in amore dramatic visual “popping out” of the impressed pattern, may be moreeffectively enhanced when substantially all fibers forming the nonwovenare white-tinted/opacified, rather than just one layer, or only some ofthem. Accordingly, it is believed desirable that awhite-tinting/opacifying agent be added to all polymer resin that isspun to make the nonwoven, rather than just that portion of resin thatis supplied to a first beam or die leading to a first bank ofspinnerets. It is believed that adjusting the opacity of the nonwovenweb, through addition of an opacifying agent, may be desirable, suchthat the nonwoven web has an Opacity of at least 36, more preferably atleast 42, and still more preferably at least 45.

While a variety of whitening/opacifying agents may suffice, it isbelieved that titanium dioxide (TiO₂) may be particularly effectivebecause of its brightness and relatively high refractive index. It isbelieved that addition of TiO₂ to the polymer(s) from which the fibersare to be formed, in an amount up to 5.0% by weight of the nonwoven, maybe effective to achieve the desired results. However, because TiO₂ is arelatively hard, abrasive material, inclusion of TiO₂ in amounts greaterthan 5.0% by weight may have deleterious effects, including wear and/orclogging of spinnerets; interruption and weakening of the structure ofthe fibers and/or calender bonds therebetween; undesirably increasingthe surface friction properties of the fibers (resulting in a lesssmooth tactile feel); and unacceptably rapid wear of downstreamprocessing equipment components. While 5.0% by weight TiO₂ may be anupper limit, if may be more desirable to include no more than 4.0% oreven no more than 3.0% by weight TiO₂. In order to desirably affect theappearance of the visible outer-facing side of the nonwoven, each layermay include a minimum of 1.5%, to 3%, by weight TiO₂, more preferably1.5% to 2%, and even more preferably, about 1.75%. It is believed thatthe increased opacity provided by whitener added to the layers of theouter-facing visible side helps to produce the visually distinctiveappearance of the nonwoven.

Spunbonding includes the step of calender-bonding the batt of spunlaidfibers, to consolidate them and bond them together to some extent tocreate a fabric-like structure and enhance mechanical properties e.g.,tensile strength, which may be desirable so the material cansufficiently maintain structural integrity and dimensional stability insubsequent manufacturing processes, and in the final product in use.Calender-bonding may be accomplished by passing the batt through the nipbetween a pair of rotating calender rollers, thereby compressing andconsolidating the fibers to form a web. One or both of the rollers maybe heated, so as to promote plastic deformation, intermeshing and/orthermal bonding/fusion between superimposed fibers compressed at thenip. The rollers may form operable components of a bonding mechanism inwhich they are urged together by a controllable amount of force, so asto exert the desired compressing force/pressure at the nip. In someprocesses heating may be deemed unnecessary, since compression alone maygenerate sufficient energy within the fibers to effect bonding,resulting from rapid deformation and frictional heat generated in thefibers as they are urged against each other where they are superimposed,resulting in plastic deformation and intermeshing, and possibly thermalbonding/fusion. In some processes an ultrasonic energy source may beincluded in the bonding mechanism so as to transmit ultrasonic vibrationto the fibers, again, to generate heat energy within them and enhancebonding.

One or both of the bonding rollers may have their circumferentialsurfaces machined, etched, engraved or otherwise formed to have thereona pattern of protrusions and recessed areas, so that bonding pressureexerted on the batt at the nip is concentrated at the outward surfacesof the protrusions, and reduced or substantially eliminated at therecessed areas. As a result, an impressed pattern of bonds betweenfibers forming the web, somewhat corresponding to the pattern ofprotrusions on the roller, is formed on the nonwoven web. One roller mayhave a smooth, unpatterned cylindrical surface, and the other may beformed with a pattern as described; this combination will impart apattern on the web somewhat reflecting the pattern on the formed roller.In some examples both rollers may be formed with patterns, and inparticular examples, differing patterns that work in combination toimpress a combination pattern on the web such as described in, forexample, U.S. Pat. No. 5,370,764.

A repeating pattern of protrusions and recessed areas such as, forexample, depicted in FIG. 3A, may be formed onto one roller. The smallershapes depicted in FIG. 3A represent outlines of rhombus- ordiamond-shaped raised surfaces 100 of protrusions, while the areasbetween them represent recessed areas 101. Each protrusion surface maybe imparted with a width W_(P1) (relative the machine direction MD) anda length L_(P1), such that each protrusion surface 100 has an area.Without intending to be bound by theory, it is believed that the visualimpact of the bond impressions impressed on the web, as well as thetensile strength, resulting from the protrusion surfaces 100, may beaffected by the area of the protrusion surfaces 100. Accordingly, it isbelieved desirable that the average area of the individual protrusionsurfaces 100 be from 0.74 mm² to 1.12 mm², or from 0.84 mm² to 1.02 mm²,or even from 0.88 mm² to 0.98 mm². Protrusion surfaces 100 may havediamond shapes as shown, or may have any other suitable shape, althoughit is believed that a diamond, rectangle, square or oval shape may havethe desirable effect of simulating the appearance of stitching, as in aquilt.

As can be seen in FIG. 3A, protrusion surfaces 100 may be arranged suchthat they substantially circumscribe a repeating pattern of recessedareas 101 in the form of geometric shapes. The geometric shapes may becontiguously arranged as depicted. The geometric shapes may be diamondsor squares, as depicted (and illustrated by dotted outlines 102 a, 103 ain FIG. 3A), or may have other shapes, including but not limited totriangles, diamonds, parallelograms, other polygons, circles, hearts,moons, etc. In FIG. 3A, it can be seen also that the pattern ofgeometric shapes repeats in the machine and cross directions atfrequencies determined by the dimensions of the shape circumscribed byoutline 103 a, where outline 103 a is drawn through the centers of theprotrusion surfaces 100. It can be seen that the dimensions of the shapecircumscribed by outline 103 a correspond with shape length L_(S1) andshape width W_(S1) as shown in FIG. 3A. (Again, length and width aredesignated with reference to the machine direction MD.) Withoutintending to be bound by theory, within the ranges of basis weights ofspunbond nonwoven materials contemplated herein, it is believed that thesize of the repeating geometrically-shaped recessed areas 101 may beimpactful with respect to optimizing both the apparent and actualdesired visible “pop” of the pattern.

It may be desired that the shapes circumscribed by the bond impressionsrepeat at a frequency of from 99 to 149, or from 105 to 143, or evenfrom 111 to 137 per meter, in either or both the machine and crossdirections, on the nonwoven web. Referring to FIG. 3B, for example, thiswould means that length L_(S2) and/or width W_(S2) may each be about 6.7mm to 10.1 mm, or from 7.0 mm to 9.5 mm, or even from 7.3 mm to 9 mm.Alternatively, it may be desired that the repeating shapes defined bythe bond impressions (for example, as illustrated/suggested by therepeating square or diamond shape defined by outline 103 a, FIG. 3A),have areas from 52 mm² to 78 mm², or from 55 mm² to 75 mm², or even from58 mm² to 72 mm².

As noted, calender-bonding may be used to consolidate the spunlaid fiberbatt into a fabric-like nonwoven web and to impart mechanical strength,e.g., tensile strength, to the web. Generally, within the rangescontemplated herein, greater percentages of protrusion surface area tototal patterned roller surface area on a roller formed with a givenpattern impart greater tensile strength to the web, than lesserpercentages. However, this may come at the cost of added stiffness inthe web, which may negatively impact tactile softness attributes. It isbelieved that a suitable balance between imparting sufficient tensilestrength for subsequent processing and satisfactory structural strengthin the finished product, and preserving tactile softness attributes, maybe struck when the ratio of area of the protrusion surfaces (e.g.,protrusion surfaces 100, FIG. 3A) to the total patterned roller surfacearea is from 16% to 35%, or from 17% to 30%, or even from 18% to 25%.

It will be noted in FIG. 3A that protrusion surfaces 100 appear to forminterrupted paths, in the example depicted, along directions indicatedby arrows 104 a, 104 b. Without intending to be bound by theory, it isbelieved that the interruptions provide at least two beneficial effects.First, it is believed that the resulting bond impressions in the webhave the effect of simulating the appearance of stitching, as in aquilt. Second, it is believed that the interruptions in the bond pathsprovide a multitude of natural hinge points at which the web may flexabout the discrete bonds, helping to preserve or enhance pliability inthe web despite the presence of the bonds. When a spunlaid batt ispassed through a nip formed by a calendering roller having the patterndepicted in FIG. 3A, bonds among and between the fibers are formedbeneath protrusion surfaces 100. If these surfaces were continuous alongdirections 104 a, 104 b instead of interrupted as shown, the resultingbonds would also be substantially continuous along those directions.This could cause the resulting nonwoven web to be more stiff and lesspliable, undesirably comprising its tactile softness attributes.

It will also be noted in FIG. 3A that the directions 104 a, 104 bfollowed by the bonding pattern paths may be diagonal with respect tothe machine direction. The bond paths imposed on the resulting web willbe similarly diagonal with respect to the machine direction. Withoutintending to be bound by theory, and relative to the use of increasedcalender-bonding pressure and/or roller temperature to form more fullydeveloped bonds as described herein, it is believed that these paths,when formed of more fully-developed bonds, comprise diagonal paths orlinear zones along which the nonwoven web has relatively higher tensilestrength and resistance to elongation. It is believed that aninteresting effect may result. When these paths are diagonal relativethe machine direction and in a criss-crossing pattern as depicted, anet-like structure may be present within the web. As a result, drawingthe nonwoven web under tension in the machine direction (as it would bedrawn in downstream manufacturing processes, e.g., laminating thenonwoven with a polymer film to form backsheet material) may have theeffect of causing the geometric shapes 101 to slightly protrude or “pop”in the z-direction out of the general plane of the web material surfaceas it narrows in width (exhibiting Poisson effect behavior), or “necks”slightly, as a result of forces within the material under tension in themachine direction, influenced by the net-like structure of diagonalpaths of higher tensile strength formed by the bonds.

It is believed that a pattern of diagonally-oriented bonding paths, assuggested in FIGS. 3A and 3B, may be more effective for producing thez-direction “pop” effect described above, than other possibleconfigurations. It is believed, further, that along suchdiagonally-oriented bonding paths, a greater percentage of bondedmaterial along the paths will have a more dramatic impact than a lesserpercentage, because the bonding results in the above-mentioned effect offorming a line along the nonwoven of relatively greater tensile strengthand resistance to elongation. Thus, referring to FIG. 3B, it can be seenthat a line 105 can be traced a path of bond impressions 100 a (line 105is drawn through the centers of bond impressions 100 a, in the depictedexample). In order that path 105 exhibits sufficiently greater tensilestrength and resistance to elongation than neighboring/parallel lines orpaths in the material, it may be desirable that the Bond Length Ratio ofa segment along line 105 is between 35% and 99%. However, as noted, itmay be desirable not to impart too much stiffness to the web (whichcompromises a tactile softness attribute). Thus, it may be desirablethat the Bond Length Ratio of a bond path be between 35% and 80%, morepreferably between 35% and 65%, and even more preferably between 35% and55%.

It has been learned that more fully-developed bonds and a morehighly-defined bond pattern may be more effectively achieved when theprotrusion surfaces 100 are polished such that they are relativelysmooth, rather than having a rougher, machined surface.

In order to complement the z-direction “pop” effect, in which thematerial forming unbonded areas 101 a protrudes out of the general planeapproximated by the web surface, it may be desirable that the pattern ofbond impressions 100 a (e.g., FIG. 3B) be distinct to the naked eye. Inorder to achieve this, sufficient force between the calendering rollersshould be applied, in combination with sufficient heating temperature.As a result, a visibly distinct pattern of bonds may be achieved, andthis pattern will have measurable features. Depending upon bondingpressure and temperature used, the shape and area of the protrusionsurfaces 100 will be somewhat reflected in the shape and area of thebond impressions in the nonwoven web. Generally it may be desired thatcalender bonding pressure and/or roller temperature be adjusted so as tocause the shape and area of protrusion surfaces 100 to be substantiallyreflected in the shape and area of the bond impressions.

It was previously believed that relatively lighter calender bondingpressures and/or relatively cooler bond roller temperatures wererequired for calender bonding, to avoid tightly binding down fibers,such that they were no longer available to be fluffed by downstreamhydroengorging processes intended to enhance visual and tactile softnessattributes. Similarly, while creating more fully developed bonds wasthought to be required to improve tensile strength properties, it wasbelieved that creating more fully-developed, rigid bonds throughrelatively greater calendering pressures and/or roller temperatureswould have the effect of undesirably increasing stiffness of thenonwoven, unacceptably compromising its tactile softness attributes. Inshort, it was believed that to preserve or gain tactile and visualsoftness signals, it was necessary to compromise tensile strength.

However, it has been discovered, surprisingly, that under thecircumstances and conditions described herein, negative effects ofgreater bonding pressures and/or temperatures upon tactile softnessattributes may be insubstantial and/or may be overcome by the positiveeffects upon visual softness attributes. More particularly, it has beendiscovered that a more highly-defined bond pattern and quilt “pop” maybe enabled through use of relatively increased calender bondingpressures and/or roller temperatures, resulting in more fully-developedbonds, which appears to be effective at creating a product that createsoverall visual impressions of softness that may overcome any negativeeffects upon tactile softness signals resulting from increased stiffnessin the material.

Further, it has been discovered, surprisingly, that one tactile softnesssignal, pliability (sometimes known as “drape”), can be substantiallymaintained or only insubstantially affected with the nonwoven materialsunder circumstances contemplated herein, even where more fully developedbonds are created, using bond patterns having features such as thosedescribed above. Without intending to be bound by theory, it is believedthat interruptions in the bond paths, for example, such as thosedescribed above (e.g., interruptions 106, FIG. 3B), may provide naturalhinge points at which the material may flex easily about bonds, even inthe presence of more fully developed bonds. Although the phenomenon isnot thoroughly understood, it is believed that this hinge effect,combined with the multitude of relatively small bond sites separated byunbonded areas such as described and depicted herein (e.g., unbondedareas 101 a, FIG. 3A), result in effective substantial preservation ofpliability or drape even when the bond sites are more fully developedthrough relatively increased calender bonding pressures and/ortemperatures.

At the same time, creating more fully developed bond sites may addtensile strength in the machine and/or cross directions. Thus,counterintuitively, it has been discovered that tensile strength can besubstantially increased through creation of more fully developedcalender bonds, without a corresponding, deleteriously substantialnegative effect on a tactile softness signal, pliability. This effectmay be achievable using features of roller patterns as described herein,with suitably adjusted calender force/pressure and roller temperature,to impress a Bond Area Percentage in the nonwoven web of at least 10%,preferably not more than 20%, more preferably 10% to 17%, and even morepreferably 10% to 15%.

Referring to FIGS. 3A and 3B by way of example, it is believed that thesize, shape and area of bond impressions 100 a in the nonwoven webproduct will somewhat, but not identically, reflect the size, shape andarea of calender roller protrusion surfaces 100. It is believed that theextent to which the area(s) of bond impressions 100 a reflect thearea(s) of roller protrusion surfaces 100 may be affected by the bondingforce/pressure between the calender rollers at the nip, and/or theroller temperature, and generally, that increasing bondingforce/pressure and/or roller temperature will increase the area of bondimpressions 100 a relative the area of protrusion surfaces 100. Thus, ifthe area of a protrusion surface 100 is from 0.74 mm² to 1.12 mm², orfrom 0.84 mm² to 1.02 mm², or even from 0.88 mm² to 0.098 mm² as setforth above, it is believed that generally the area of a correspondingbond impression will be somewhat less. In order to achieve the visiblyimproved results realized in Example 2 herein, bond impressions 100 awere created having an average surface area of 0.57±0.06 mm², resultingfrom protrusion surfaces 100 having an average surface area ofapproximately 0.93 mm². In a prior version, using the same basis weightspunbond batt and the same rollers, the resulting average bondimpression surface area was measured as 0.27±0.02 mm², resulting from arelatively lighter calender pressure and/or roller temperature. It isbelieved that an increase in calender pressure and/or roller temperatureis at least partially the cause for the difference.

Following calender bonding, the web may be subjected to ahydroengorgement process such as described in U.S. Pat. App. Pub. No.2006/0057921. A distinguishing feature of hydroengorgement, as comparedwith traditional hydroentanglement, is the use of hydraulic jets toenhance the loft and softness attributes of a nonwoven. However, prioruse of hydroengorgement has not been fully satisfactory for providing anonwoven having both improved softness and a bond pattern with avisually distinct appearance. The '921 application describes ahydroengorgement process involving particular ranges of pressure, e.g.,180-240 bar (2,610-3,480 p.s.i.) applied to the water jet orifices,which was believed required to obtain a desired amount of fluffing ofthe nonwoven fibers, adding apparent and actual loft or caliper.However, it has been discovered that substantially reducing thehydroengorgement pressure from these magnitudes may still providedesired fluffing without deleterious effects. It is believed thathydroengorgement pressures of the magnitude specified in the '921application may result in a loss of distinctiveness and/or obscuring ofthe pattern of bond impressions. Substantially reducing hydroengorgementpressure and energy, and directing hydroengorgement jets at only theinner-facing surface of the nonwoven (thus urging fibers/portionsthereof impinged by water jets toward the outer-facing surface) appearsto have had a contribution to improving the definition and visual “pop”of the quilt appearance on the outer-facing surface imparted by theroller pattern. A reduced pressure of about 25-100 bars (360-1,450p.s.i.) may be employed for hydraulic treatment. More preferably, twoinjectors, each at about 50 bars (725 p.s.i.) of pressure are used,providing an energy transmission of about 0.02 kwhr/kg. It is believedthat the use of a one-sided hydroengorgement significantly improves thesoftness attributes of the nonwoven while pushing fibers in between bondareas to create a more pronounced appearance. Further, thehydroengorgement may enhance the resilience of the pattern such that itcan maintain a pronounced appearance after being processed into anarticle and packaged.

In addition to the features, methods and materials described above, itis believed that the manner in which the nonwoven web is adhered to thepolymeric film, to form a backsheet laminate, may have an impact on thequilted appearance of the backsheet. In particular, use of athermoplastic polymeric hot melt adhesive to adhere the nonwoven web toa thin polymeric film to form a backsheet laminate may enhance thequilted appearance. Without intending to be bound by theory, it isbelieved that, following lamination, the adhesive contracts slightly asit cools, causing the film, and correspondingly, the laminate, to puckerslightly. This may contribute to causing the unbonded areas of thenonwoven (e.g., unbonded areas 101 a, FIG. 3b ), to protrude or popslightly in the z-direction.

If this theory is correct, it may also be desired to apply the hot meltadhesive in a pattern such that adjacent areas and patterns of thenonwoven and polymer film are adhered and not adhered. This allowsunadhered areas of the nonwoven to pop in the z-direction away from thefilm when the laminate is shifted about, such as during handling orwear, contributing to the quilted appearance. Accordingly, in oneexample, adhesive may be applied in 1 mm wide strips extending along themachine direction, at 3 to 4 strips per centimeter along the crossdirection. In another example, adhesive may be applied in a spiralpattern, or series of spiral patterns, leaving unadhered areassurrounded and interspersed with adhered areas.

Further, the polymer film may be stretched slightly in the machinedirection prior to, and maintained in the stretched condition during,lamination to the nonwoven web. In this event, subsequent relaxation andelastic contraction of the film following lamination may cause slightmachine direction compression of the nonwoven web and thereby promotez-direction protrusion of unbonded areas thereof, potentially enhancingvisual “pop” by yet another mechanism. A polymer film may be stretchedfrom 1% to 5% in machine-direction length prior to lamination, or morepreferably, from 2% to 4%.

Example 1

An exemplary embodiment of the present invention, Sample A, was aspunbond nonwoven made in a four beam process, laying down four layers(layers A, B, C, D) of fibers, two layers formed of ExxonMobil 3155polypropylene and two layers formed of ExxonMobil SFT315 polypropyleneblend with the bottom layers of the nonwoven being made from ExxonMobil3155. Each layer contained 2.5% by weight of a master batch containingabout 30% by weight polypropylene and 70% TiO₂ (a whitener),corresponding to about 1.75% by weight TiO₂ for the layer. The spunbondnonwoven was bonded using the bond pattern described for Example 2below. The bottom side of the nonwoven was hydraulically treated usingtwo rows of jets, each at 50 bars (725 p.s.i.) pressure, for a totalenergy transmission of 0.02 kwhr/kg.

By comparison, Control A was made from the same nonwoven substrate andbond pattern with only about 0.3% of whitener in each layer. Further,Control A was hydroengorged using a hydraulic treatment on both sides ofthe nonwoven each side being subjected to a row of jets at a pressure of240 bars (3,480 p.s.i.).

An additional sample, Control B was made from the same nonwoven with thesame processing conditions as Sample A but without any hydraulictreatments.

A third sample, Control C was made with the same nonwoven as Sample Ahowever the whitener distribution was limited to 1.6% on the top layerswith no whitener on the bottom layers. The nonwoven was hydroengorgedusing 2 injectors at 100 bars (1,450 p.s.i.) pressure on the top side,followed by 2 injectors at 250 bars (3,626 p.s.i.) pressure on thebottom side.

In a comparison, Sample A had a significantly improved appearance overControl A, both in raw nonwoven form and when incorporated into anarticle. Sample A also had an improved appearance over Control B and asignificantly improved softness as measured by a panel of testers. Incomparison to Sample A, Control C had an inferior visual appearanceafter manufacture and showed significant deterioration in appearanceafter being incorporated into an article and packaged. Table 1 setsforth properties of Control A, Control B, Control C and Sample A.

TABLE 1 Description Control A Control B Control C Sample A ProcessConditions Whitener Distribution (layers A-D), 0.3 × 4 2.5 × 4 1.6, 1.6,0, 0 2.5 × 4 weight % Spinbelt speed, meters/m 420 440 420 440 HEInjector Pressures, C1, C2, bar 1 × 240, 1 × 240 2 × 0, 2 × 0 2 × 100, 2× 250 2 × 0, 2 × 50 HE Energy, kwhr/kg 0.20 0.00 0.26 0.02 PhysicalProperties Basis Weight, gsm 26.1 24.7 24.9 24.1 MD Tensile Strength,gf/cm 795 918 673 938 MD Elongation, % 39.5 55.7 36.9 43.1 CD TensileStrength, N/cm 489 449 347 489 CD Elongation, % 58.6 63.0 59.3 65.7MD:CD 1.62 2.05 1.95 1.92 Air Perm, m³/m²/min 170 163 192 171 Caliper,mm — 0.275 0.271 0.296 Opacity, % 33.2 47.8 33.6 45.7 Hand Panel SurveyNot Tested 0 Not Tested 10 Quilt Definition of Nonwoven Poor Very GoodGood Excellent Quilt Definition after Packaging Poor Fair Excellent

Example 2

An improved backsheet laminate including an improved spunbond nonwovenweb laminated/adhered to a polymeric film was manufactured. The nonwovenweb was calender-bonded in a pattern, between the nip between a patterncalender roller and a smooth calender roller as described herein, toimpart a pattern of bond impressions as schematically suggested in FIG.3B. The improved web had a basis weight of about 25 gsm and comprisedPP.

The web was manufactured by First Quality Nonwovens, Inc., Great Neck,N.Y., using a calender roller bearing a repeating “P11” pattern asschematically depicted in FIG. 3A, as provided by The Procter & GambleCompany, Cincinnati, Ohio, and manufactured by Ungricht Roller &Engraving Technology (A.+E. Ungricht GmbH+Co KG), Mönchengladbach,Germany. Referring to FIG. 3A, the engraving/machining specificationsfor the roller pattern were such that W_(S1) and L_(S1) were each 8.077mm; W_(P1) was 1.69 mm; and L_(P1) was 1.1 mm, such that the protrusionsurface 100 areas were each 0.93 mm².

The improved laminate had a dramatically improved, visually distinctquilted appearance and exhibited a dramatically improved visible patternof light and shadow under varying lighting conditions, as compared withprior versions. The bond impressions were more visible to the naked eye,and more clearly defined. The Total Bond Area was estimated from themeasured Average Individual Bond Area and the roller pattern repeatdimensions (8.077 mm each way) as approximately 12% to 13%.

Various features of the resulting improved nonwoven web and laminatewere measured and compared with those of prior versions of nonwoven websand laminates formed therewith, and having similar calender bondingpatterns. It is believed the improved quilted appearance resulted from acombination of one or more of increased Opacity, increased AverageMeasured Height, increased Average Individual Bond Area and/or otherfeatures. As can be seen in Table 2, the improved nonwoven web also hadimproved tensile strength in both machine and cross directions over theprior versions, except for machine direction tensile strength comparedwith prior version C; but version C had approximately 52% greater basisweight.

TABLE 2 Nonwoven Nonwoven Nonwoven Web MD Web CD Nonwoven AverageAverage Basis Weight Tensile Tensile Opacity of Total MeasuredIndividual (gsm)/ Strength Strength Opacity of Nonwoven Stiffness HeightBond Area Sample construction (gf/cm) (gf/cm) Laminate Web (g/f) (μm)(mm²) Improved ~25/spunlaid 970 441 76 52 8.7 318 0.57 Prior~25/spunlaid 679 298 72 34 7.4 170 0.27 Version A Prior ~25/spunlaid 822266 68 32 6.6 274 0.27 Version B bicomponent fiber Prior ~38/carded1,051 181 70 39 13.9 354 0.54 Version C

In-Bag Compression Measurement Test I. Determine Free Stack Height

Equipment

-   -   Universal Diaper Packaging Tester (UDPT), including a vertical        sliding plate for adding weights. It is counter-balanced by a        suspended weight to assure that no downward force is added from        the vertical sliding plate assembly to the diaper package at all        times. The UDPT is available from Matsushita Industry Co. LTD,        7-21-101, Midorigaoka-cho, Ashiya-city, Hyogo JAPAN. Zip code:        659-0014. For further details concerning this Tester, see U.S.        Pat. App. Pub. No. 2008/0312624.    -   A 850 g (±5 g) weight.    -   Stopwatch with an accuracy to 1 second.

Test Procedure

A) Apparatus Calibration

-   -   Pull down the vertical sliding plate until its bottom touches        the tester base plate.    -   Set the digital meter located at the side of the vertical        sliding scale to zero mark.    -   Raise the vertical sliding plate away from the tester base        plate.

B) Definitions

-   -   Before-bagger free height refers to the free height data        measured on 10 pads of fresh diapers.    -   Fresh Diapers—10 diapers that have never been compressed (stack        should be removed (where safely possible) immediately after exit        from stacker, before any compression has occurred. If this is        not possible, they should be removed from the fingers of a        safely stopped stacker chain).    -   Out-bag free height designates the free height data measured on        10 pads of aged diapers.    -   Aged Diapers—10 diapers that have been held under compression        for approximately 1 minute and/or longer (i.e. 10 diapers come        from a freshly opened diaper package).

C) Free Height Measurement

-   -   Select 10 adjacent pads of diapers out of the middle from an        appropriate source; Fresh diapers for before-bagger free height;        Aged diapers for out-of-bag free height.    -   Neatly stack these 10 pads of diapers underneath the vertical        sliding plate. (Align the center of the top pad directly below        the central counter sunk hole of the vertical sliding plate.) •        Place the 850 g weight onto the vertical sliding plate.    -   Allow the vertical sliding plate to slide down until its bottom        lightly touches desired highest point of the stack.    -   Measure the stack dimensions in mm by reading the value that        appears on the digital meter.    -   Remove the weight.    -   Raise the vertical sliding plate away from the stack and remove        the stack.    -   Record the stack height reading to the nearest 1 mm shown on the        digital meter.

Procedure—Aging Profile

-   -   A) Collect a minimum of three data points from different sample        sets e.g., Measure first point from fresh diapers, e.g., measure        second point from diapers being aged in bag for 30 mm/1 hr/6        hr/12 hr/24 hr, e.g., measure third point from diapers being        aged in bag for 5 days or longer.    -   B) Repeat the three steps as described in “Test Procedure” steps        A), C), and D).

Procedure—Out-of-Bag Free Height Recovery

-   -   A) Collect 10 pads of fresh/aged diapers.    -   B) Repeat the first two steps as described in “Test Procedure”        steps A) and C).    -   C) Repeat the steps above for general free height measurement        except changing the waiting time (i.e., measure first point at 1        min and remaining points at 30 mm/1 hr/6 hr/12 hr/I day/3 days/5        days, or longer).

Calculation/Reporting

-   -   Report Sample Identification, i.e. complete description of        product being tested (product brand name/size).    -   Report the determined value for all measurement to the nearest 1        mm.

NOTE: In case of a series of measurements report the number of testedsamples, and calculate/report the Average, Standard deviation, Minimumand Maximum of the values.

-   -   Report the Production Date of the measured package (taken from        package coding).    -   Report the Testing Date and Analytical Method used (GCAS).

II. Determine in-Bag Stack

Equipment

-   -   Universal Diaper Packaging Tester (UDPT), including a vertical        sliding plate for adding weights. It is counter-balanced by a        suspended weight to assure that no downward force is added from        the vertical sliding plate assembly to the diaper package at all        times. The UDPT is available from Matsushita Industry Co. LTD,        7-21-101, Midorigaoka-cho, Ashiya-city, Hyogo JAPAN. Zip code:        659-0014.    -   A 850 g (±5 g) weight.

Definitions

-   -   “Package Width” is defined as the maximum distance between the        two highest bulging points along the same compression stack axis        of a diaper package.    -   In-Bag Stack Height=(Package Width I Pad Count Per Stack)×10        pads of diapers.

Apparatus Calibration

-   -   Pull down the vertical sliding plate until its bottom touches        the tester base plate.    -   Set the digital meter located at the side of the vertical        sliding scale to zero mark.    -   Raise the vertical sliding plate away from the tester base        plate.

Test Procedure

-   -   Put one of the side panel of the diaper package along its width        standing at the center of the tester base plate. Make sure the        horizontal sliding plate is pulled to the right so it does not        touch the package being tested.    -   Add the 850 g weight onto the vertical sliding plate.    -   Allow the vertical sliding plate to slide down until its bottom        lightly touches desired highest point of the package.    -   Measure the package width in mm (distance from the top of the        base plate to the top of the diaper package). Record the reading        that appears on the digital meter.    -   Remove the 850 g weight.    -   Raise the vertical sliding plate away from the diaper package.    -   Remove the diaper package.

Calculation/Reporting

-   -   Calculate and report the “In-Bag Stack Height”=(Package Width I        Pad Count Per Stack)×10.    -   Report Sample Identification, i.e. complete description of        product being tested (product brand name/size).    -   Report the determined value for each measurement        (Length/Width/Front-to-Back) to the nearest 1 mm.

NOTE: In case of a series of measurements report the number of testedsamples, and calculate/report the Average, Standard deviation, Minimumand Maximum of the values.

-   -   Report the Production Date of the measured package (taken from        package coding).    -   Report the Testing Date and Analytical Method used (GCAS).

III. Calculate %

Calculate %: 1−(In-Bag Stack Height)/(Free Stack Height)=%

Opacity Measurement Method

The opacity of a material is the degree to which light is blocked bythat material. A higher opacity value indicates a higher degree of lightblock by the material. Opacity may be measured using a 0°illumination/45° detection, circumferential optical geometry,spectrophotometer with a computer interface such as the HunterLab LabScan XE running Universal Software (available from Hunter AssociatesLaboratory Inc., Reston, Va.). Instrument calibration and measurementsare made using the standard white and black calibration plates providedby the vendor. All testing is performed in a room maintained at about23±2° C. and about 50±2% relative humidity.

Configure the spectrophotometer for the XYZ color scale, D65 illuminant,10° standard observer, with UV filter set to nominal. Standardize theinstrument according to the manufacturer's procedures using the 1.20inch port size and 1.00 inch area view. After calibration, set thesoftware to the Y opacity procedure.

To obtain the specimen, lay the sample flat on a bench, body facingsurface downward, and measure the total longitudinal length of thearticle. Note a site 33% of the total length from the front waist of thearticle along the longitudinal axis and a second site, 33% of the totallength from the back waist of the article. Carefully remove thebacksheet laminate, consisting of both the film and nonwoven web, fromthe garment-facing side of the article. A cryogenic spray, such asCyto-Freeze (obtained from Control Company, Houston, Tex.), may be usedto separate the backsheet laminate from the article. Cut a piece 50.8 mmby 50.8 mm centered at each site identified above. Precondition samplesat about 23° C.±2 C.° and about 50%±2% relative humidity for 2 hoursprior to testing.

Place the specimen over the measurement port. The specimen shouldcompletely cover the port with the surface corresponding to thegarment-facing surface of the article directed toward the port. Coverthe specimen with the white standard plate. Take a reading, then removethe white tile and replace it with black standard tile without movingthe specimen. Obtain a second reading, and calculate the opacity asfollows:

Opacity=Y value_((black backing)) /Y value_((white backing))×100

A total of five identical articles are analyzed and their opacityresults recorded. Calculate and report the average opacity and standarddeviation for the 10 backsheet laminate measurements to the nearest0.01%.

Using the same specimens as above, remove the nonwoven web from the filmlayer for analysis. The cryogenic spray can once again be employed.Precondition samples at about 23° C.±2 C.° and about 50%±2% relativehumidity for 2 hours prior to testing. In like fashion, analyze thenonwoven web layer following the above procedure. Calculate and reportthe average opacity and standard deviation for the 10 nonwoven webmeasurements to the nearest 0.01%.

Average Measured Height Method

Average Measured Height is measured using a GFM Primos Optical Profilerinstrument commercially available from GFMesstechnik GmbH,Teltow/Berlin, Germany. The GFM Primos Optical Profiler instrumentincludes a compact optical measuring sensor based on digitalmicro-mirror projection, consisting of the following main components: a)DMD projector with 1024×768 direct digital controlled micro-mirrors; b)CCD camera with high resolution (1300×1000 pixels); c) projection opticsadapted to a measuring area of at least 27×22 mm; d) recording opticsadapted to a measuring area of at least 27×22 mm; e) a table tripodbased on a small hard stone plate; f) a cold light source (anappropriate unit is the KL 1500 LCD, Schott North America, Inc.,Southbridge, Mass.); g) a measuring, control, and evaluation computerrunning ODSCAD 4.14-1.8 software; and h) calibration plates for lateral(x-y) and vertical (z) calibration available from the vendor.

The GFM Primos Optical Profiler system measures the surface height of asample using the digital micro-mirror pattern fringe projectiontechnique. The result of the analysis is a map of surface height (zaxis) versus displacement in the x-y plane. The system has a field ofview of 27×22 mm with a resolution of 21 microns. The height resolutionshould be set to between 0.10 and 1.00 micron. The height range is64,000 times the resolution. All testing is performed in a conditionedroom maintained at about 23±2° C. and about 50±2% relative humidity.

To obtain the specimen, lay the sample flat on a bench, body facingsurface downward, and measure the total longitudinal length of thearticle. Note a site 33% of the total length from the front waist of thearticle along the longitudinal axis and a second site, 33% of the totallength from the back waist of the article. Carefully remove the nonwovenouter cover from the garment-facing side of the article. A cryogenicspray, such as Cyto-Freeze (obtained from Control Company, Houston,Tex.), may be used to separate the nonwoven from the underlying filmlayer. Cut a piece 40 mm by 40 mm centered at each site identifiedabove. Precondition samples at about 23° C.±2 C.° and about 50%±2%relative humidity for 2 hours prior to testing.

Turn on the cold light source. Select settings on the cold light sourceto give a reading of 3000K on the display (typically 4 and E). Open theODSCAD 4.14-1.8 Software and select “Start Measurement” and then “LivePic”. Calibrate the instrument according to manufacturer'sspecifications using the calibration plates for lateral (x-y) andvertical (z) available from the vendor.

Place the 40 mm by 40 mm specimen of nonwoven outer cover, clothingsurface upward, under the projection head and on top of a neutral graysurface (WhiBal White Balance Reference, PictureFlow LLC, Melbourne,Fla.). Ensure that the sample is lying flat, without being stretched.This may be accomplished by taping the perimeter of the sample to thesurface or placing it under a weighted frame with an inside dimension of30 mm×30 mm.

Using the “Pattern” command, project the focusing pattern on the surfaceof the specimen. Position the projection head to be normal to the samplesurface. Align the projected cross hair with the cross hair displayed inthe software. Focus the image using the projector head height adjustmentknob. Adjust image brightness according to the instrument manufacturer'sinstruction by setting the “Projection” value to 10, and then changingthe aperture on the lens through the hole in the side of the projectorhead. Optimum illumination is achieved when the lighting displayindicator in the software changes from red to green. Due to variationsin instrument configurations, different brightness parameters may beavailable. Always follow the instrument manufacturer's recommendedprocedures for proper illumination optimization.

Select the Technical Surface/Standard measurement type. Operatingparameters are as follows: Utilization of fast picture recording with a3 frame delay. A two level Phasecode, with the first level being definedas an 8 pixel strip width with a picture count number of 24, and thesecond level being defined as a 32 pixel strip width with a picturecount number of 6. A full Graycode starting with pixel 1 and ending withpixel 1024. A Prefiltering routine including the removal of invalidpixels, a 5 by 5 median filter, and a 3 by 3 average filter.

Select “Measure” to capture and digitalize the image. The specimen mustremain still during this procedure to avoid blurring of the capturedimage. The image will be captured in approximately 20 seconds. Save theheight image and camera image files.

Load the height image into the analysis portion of the software via theclipboard. Zoom in on a region of interest (ROI) encompassing a singlerepeating pattern of bond impressions and unbonded area. Using thepolygon drawing tool manually outline four individual bond impressionsaround the perimeter of the unbonded area (see example in FIG. 4B). From“View” select “Histogram of height picture”. Select the number ofclasses as 200 and calculate the frequency histogram. Save the bondimpression height file. Returning to the height image, cancel thepolygon markings drawn on the bond impressions. Next, using the polygondrawing tool, manually outline the unbonded area surrounded by the bondimpressions (see example in FIG. 4A). Once again, from “View” select“Histogram of height picture”. Select the number of classes as 200 andcalculate the frequency histogram. Save the unbonded area histogramfile.

Open the histogram file of the bond impressions, determine the heightrange value at, or nearest to 50%. Record bond impression height to thenearest 1 micrometer. Open the histogram file of the unbonded area,determine the height range value at, or nearest to 90%. Record theunbonded area height to the nearest 1 micrometer. Measured Height iscalculated as follows:

Measured Height=unbonded area height−bond impression height

Measured Height is measured at two separate ROI's for each of thespecimens (i.e., from front of article and back of article) to give fourmeasures per test article. A total of three test articles are analyzedin like fashion. Calculate the Average and standard deviation for alltwelve measured Measured Heights and report to the nearest 1 micrometer.

Tensile Strength Measurement Method

Tensile Strength is measured on a constant rate of extension tensiletester with computer interface (a suitable instrument is the MTSAlliance using Testworks 4.0 Software, as available from MTS SystemsCorp., Eden Prairie, Minn.) using a load cell for which the forcesmeasured are within 10% to 90% of the limit of the cell. Both themovable (upper) and stationary (lower) pneumatic jaws are fitted withrubber faced grips, wider than the width of the test specimen. Alltesting is performed in a conditioned room maintained at about 23° C.±2C and about 50%±2% relative humidity.

To obtain the specimen for CD tensile, lay the sample flat on a bench,body facing surface downward, and measure the total longitudinal lengthof the article. Note a site 25% of the total length from the front waistof the article along the longitudinal axis and a second site, 25% of thetotal length from the back waist of the article. Carefully remove thenonwoven outer cover from the garment-facing side of the article. Acryogenic spray, such as Cyto-Freeze (obtained from Control Company,Houston, Tex.), may be used to separate the nonwoven outer cover fromthe underlying film layer. Cut a specimen, with a die or razor knife,which is 50.8 mm wide along the longitudinal axis of the sheet and least101.6 mm long along the lateral axis of the sheet, centered at each ofthe sites identified above.

In like fashion prepare MD tensile specimens from a second set ofidentical samples. Here, after removing the nonwoven outer cover, cut aspecimen, with a die or razor knife, which is at least 101.6 mm widealong the longitudinal axis of the sheet and 50.8 mm long along thelateral axis of the sheet, centered at each of the sites identifiedabove. Precondition both CD and MD specimens at about 23° C.±2 C.° andabout 50%±2% relative humidity for 2 hours prior to testing.

For analyses, set the gage length to 50.8 mm. Zero the crosshead andload cell. Insert the specimen into the upper grips, aligning itvertically within the upper and lower jaws and close the upper grips.Insert the specimen into the lower grips and close. The specimen shouldbe under enough tension to eliminate any slack, but less than 0.05 N offorce on the load cell.

Program the tensile tester to perform an extension test, collectingforce and extension data at an acquisition rate of 50 Hz as thecrosshead raises at a rate of 100 mm/min until the specimen breaks.Start the tensile tester and data collection. Program the software torecord Peak Force (gf) from the constructed force (gf) verses extension(mm) curve. Calculate tensile strength as:

Tensile Strength=Peak Force (gf)/width of specimen (cm)

Analyze all CD tensile specimens. Record Tensile Strength to the nearest1 gf/cm. Analyses are performed on specimens from the two sites on thearticle. A total of five test articles are analyzed in like fashion.Calculate and report the average and standard deviation of TensileStrength to the nearest 1 gf/cm for all ten measured CD specimens.

Next run all MD tensile Specimens. Record Tensile Strength to thenearest 1 gf/cm. Analyses are performed on specimens from the two siteson the article. A total of five test articles are analyzed in likefashion. Calculate and report the average and standard deviation ofTensile Strength to the nearest 1 gf/cm for all ten measured MDspecimens.

Image Analysis of Bond Impressions

Area and distance measurements are performed on images generated using aflat bed scanner capable of scanning at a resolution of at least 4800dpi in reflectance mode (a suitable scanner is the Epson Perfection V750Pro, Epson, USA). Analyses are performed using ImageJ software (Vs.1.43u, National Institutes of Health, USA) and calibrated against aruler certified by NIST.

To obtain the specimen, lay the sample flat on a bench, body facingsurface downward, and measure the total longitudinal length of thearticle. Note a site 33% of the total length from the front waist of thearticle along the longitudinal axis and a second site, 33% of the totallength from the back waist of the article. Carefully remove the nonwovenouter cover from the garment-facing side of the article. A cryogenicspray, such as Cyto-Freeze (obtained from Control Company, Houston,Tex.), may be used to separate the nonwoven from the underlying filmlayer. Cut a piece 80 mm by 80 mm centered at each site identifiedabove. Precondition samples at about 23° C.±2 C.° and about 50%±2%relative humidity for 2 hours prior to testing.

Place the specimen on the flat bed scanner, body side surface facingupward, with the ruler directly adjacent. Placement is such that thedimension corresponding to the MD of the nonwoven is parallel to theruler. A black backing is placed over the specimen and the lid to thescanner is closed. Acquire an image composed of the nonwoven and rulerat 4800 dpi in reflectance mode in 8 bit grayscale and save the file.Open the image file in ImageJ and perform a linear calibration using theimaged ruler. Reference will be made to FIG. 3B as an example of arepeating pattern of bond impressions. These measures are equallyapplicable to other bond shapes and repeating bond patterns.

Average Individual Bond Area

Enlarge a ROI such that edges of the bond impression can be clearlydetermined. With the area tool, manually trace the perimeter of a bond.Calculate and record the area to the nearest 0.001 mm². Repeat for atotal of ten non-adjacent bonds randomly selected across the totalspecimen. Measurements are made on both specimens from each article. Atotal of three identical articles are measured for each sample set.Calculate the average and standard deviation of all 60 bond areameasurements and report to the nearest 0.001 mm².

Bond Path/Bond Length Ratio

Identify a single, complete repeating series of bond impressions forminga path and enlarge the image such that the repeating series fills thefield of view. Draw a line along the path that connects and extendsthrough all bond impressions in the series (e.g., FIG. 3B, line 105).Measure the dimensions along the line that are included within the bondimpressions (e.g. in FIG. 3B, D₁, D₂, D₃). Next, measure the distance ofthe line segment from the leading edge of the first bond impression inthe repeating series to leading edge of the first bond impression in thenext adjacent series along the line segment (e.g. in FIG. 3B, D₀).Calculate the sum of the lengths of the bonds along the line segment(e.g. D₁+D₂+D₃), divided by the length of the line segment, (e.g. D₀),×100%. Record the Bond Path/Bond Length Ratio to the nearest 0.001.Repeat for a total of five non-adjacent ROI's randomly selected acrossthe total specimen. Measurements are made on both specimens from eacharticle. A total of three identical articles are measured for eachsample set. Calculate the average and standard deviation of all 60 bondPath/Length Ratio measurements and report to the nearest 0.001 units.Note for irregularly-shaped bond impressions forming a repeating series,locate a line so as to find the maximum sum of the lengths of the bondimpressions measurable therealong.

Bond Area Percentage

Identify a single repeat pattern of bond impressions and unbonded areasand enlarge the image such that the repeat pattern fills the field ofview. In ImageJ draw a box that encompasses the repeat pattern. For theexample shown in FIG. 3B, this would be a box, W_(S2) wide and L_(S2)long. Note, in the example shown in FIG. 3B, the shared bond impressionsat the corners are divided in half along the longitudinal or lateraldirection as appropriate. Calculate area of the box and record to thenearest 0.01 mm². Next, with the area tool, trace the individual bondimpressions or portions thereof entirely within the box and calculatethe areas of all bond impressions or portions thereof that are withinthe box. Record to the nearest 0.01 mm². Calculate as follows:

Percent Bond Area=(Sum of areas of bond impressions within box)/(area ofbox)×100%

Repeat for a total of five non-adjacent ROI's randomly selected acrossthe total specimen. Record as Percent Bond Area to the nearest 0.01%.Measurements are made on both specimens from each article. A total ofthree identical articles are measured for each sample set. Calculate theaverage and standard deviation of all 30 of the percent bond areameasurements and report to the nearest 0.001 units.

Stiffness

Stiffness of the nonwoven outer cover was measured in accordance withASTM D6828-02. For analysis a 76.2 mm by 76.2 mm square specimen wasused instead of the 100 mm by 100 mm specimen recited in the standard.

To obtain the specimen, lay the sample flat on a bench, body facingsurface downward, and measure the total longitudinal length of thearticle. Note a site 25% of the total length from the front waist of thearticle along the longitudinal axis and a second site, 25% of the totallength from the back waist of the article. Carefully remove the nonwovenouter cover from the garment-facing side of the article. A cryogenicspray, such as Cyto-Freeze (obtained from Control Company, Houston,Tex.), may be used to separate the nonwoven from the underlying filmlayer. Cut a piece 76.2 mm by 76.2 mm centered at each site identifiedabove. Precondition samples at about 23° C.±2 C.° and about 50%±2%relative humidity for 2 hours prior to testing.

Stiffness measurements are made on both specimens from each article. Atotal of three identical articles are measured for each sample set.Calculate the average and standard deviation of the six Total Stiffnessresults and report to 0.01 g.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method of manufacturing a nonwoven comprisingthe steps of: forming a nonwoven web substantially comprised ofcontinuous fibers; applying a bonding pattern to said nonwoven web usinga smooth roll and a calender roll wherein said bonding pattern comprisesa pattern having unbonded areas; and subjecting the side of saidnonwoven web contacted by said smooth roll to a hydraulic treatment at apressure of between 25 and 75 bars and a total energy of about 0.01-0.04kwhr/kg., wherein said continuous fibers are comprised of between 97%and 98.5% by weight of an olefin resin comprising substantially ofpolypropylene and between 1.5% and 3% by weight of a whitener.
 2. Themethod of claim 1 wherein said step of forming a nonwoven websubstantially comprised of continuous fibers further comprises: formingone or more spunlaid layers wherein said continuous fibers containsofteners.
 3. The method of claim 1 wherein said continuous fibers arecomprised of about 1.75% by weight of whitener.
 4. The method of claim 1wherein said nonwoven web has a substantially uniform distribution ofwhitener.
 5. The method of claim 1 wherein said step of subjecting theside of said nonwoven web contacted by said smooth roll to a hydraulictreatment comprises: subjecting the side of said nonwoven web contactedby said smooth roll to a first hydraulic treatment at a pressure ofabout 50 bars; and subjecting the side of said nonwoven web contacted bysaid smooth roll to a second hydraulic treatment at a pressure of about50 bars.
 6. The method of claim 1 wherein said nonwoven web has basisweight of between 18 and 32 gsm.
 7. The method of claim 1 wherein saidnonwoven web has a substantially uniform distribution of whitener. 8.The method of claim 1 wherein said whitener is TiO₂.
 9. The method ofclaim 2 wherein the distribution by weight of softeners in said nonwovenweb is greater on the side of said nonwoven web contacted by saidcalender roll than on the side of said nonwoven web contacted by saidsmooth roll.